The Primary Breast Cancer Therapy Group (NSABP) is a multidisciplinary cooperative group consisting of surgeons, radiation therapists, pathologists, medical oncologists and more recently nurse oncologists have been added to the group. Currently patients from all of the earliest protocols are being followed and we are participating in two ongoing protocols. We are preparing to enter three new protocols: (1) for Stage II breast cancer involving an immunotherapy arm. (2) for Stage 111 breast cancer. (3) for Colo-Rectal cancer. This institution has been a participant since 1971. The grant application is being submitted for support of our institution's participation in the protocols conducted by the Primary Breast Cancer Therapy Group (NSABP) and should be considered with the Headquarters grant applcation submitted by the Project Chairman, Dr. Bernard Fisher. In addition to participating in Protocol studies we are providing the Headquarters Office with samples of breast tumors for estrogen and more recently progesterone protein binding receptor studies. We will collect blood samples for determination of biological markers in selected patients. New protocols to evaluate segmental mastectomy, the use of the immunopotentiating agent, C. parvum, and the use of other chemotherapeutic agents are in various planning stages and should be implemented shortly for patients with Stage I and II breast cancer. A protocol for Stage III breast cancer patients is being revised and should begin shortly after approval by the National Cancer Institute. Extensive information has been obtained relative to the pathology specimens submitted by us from patients in the various protocols.